Spectroscopy is used to analyze the nature of a substance under study by measuring, for example, the optical absorbance of this substance at various wavelengths. In some applications, a light source in the form of a narrow bandwidth and wavelength variable light source is used to illuminate a substance under study, and a detector is used to measure the absorbance of the substance at many wavelengths. To get the wavelength dependency of the absorbance, the detector is typically synchronized to the light source, typically by being connected thereto, so that each absorbance measurement can be matched to a specific emitted wavelength.
This need for a connection between the detector and light source can be a problem in many applications. For example, it may be the case that the distance between the light source and the detector is relatively large. In this case, there is a need to extend a cable between the light source and the detector over a relatively large distance, and possibly over difficult terrain. Also, in some applications, the detector or the light source may be mounted to a mobile unit, such as a person or a vehicle. In these cases, the use of a cable is clearly impractical.
In other applications, a sample includes a spatial distribution of indicators that respond differently to light having different wavelengths. For examples, in cellular biology experiments, chromophores that attach to different biological structures are provided, the chromophores each reacting to a specific wavelength of light to emit light at a different wavelength, thereby allowing imaging of the spatial distribution of each chromophore. Each emitted wavelength requires its own detector that receives light that has been separated in its component wavelengths, which can result in relatively complex and expensive setups.
More generally speaking, there is a need in many fields to assess the interaction of a sample with light at different wavelengths. To that effect, light beams including each of the wavelengths are used to irradiate the sample in succession. However, transmitting the information about which wavelength is used to a detector that detects the light resulting from the interaction of the sample with each light beams can be impractical. Also, transmission of this information can cause synchronization problems and can reduce the speed at which the light beams can be switched from one to the other.
Against this background, there exists a need in the industry to provide an improved method for assessing an interaction of a sample with light beams having different wavelengths and an apparatus for performing the same. An object of the present invention is therefore to provide such a method for assessing an interaction of a sample with light beams having different wavelengths and such an apparatus for performing the same.